package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.entity.Shop;
import com.hmdp.mapper.ShopMapper;
import com.hmdp.service.IShopService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.CacheClient;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.RedisData;
import com.hmdp.utils.SystemConstants;
import org.springframework.data.geo.Distance;
import org.springframework.data.geo.GeoResult;
import org.springframework.data.geo.GeoResults;
import org.springframework.data.redis.connection.RedisGeoCommands;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.domain.geo.GeoReference;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;

import java.time.LocalDateTime;
import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class ShopServiceImpl extends ServiceImpl<ShopMapper, Shop> implements IShopService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private CacheClient cacheClient;

    @Override
    public Result queryById(Long id) {
        //缓存穿透
//        Shop shop = cacheClient.queryWithPassThrough(CACHE_SHOP_KEY,id, Shop.class,this::getById,CACHE_SHOP_TTL,TimeUnit.MINUTES);
//        Shop shop = queryWithMutex(id);
        Shop shop = cacheClient.queryWithLogicalExpire(
                CACHE_SHOP_KEY,id,Shop.class,this::getById,10L,TimeUnit.SECONDS);
        if (shop == null){
            return Result.fail("店铺不存在！");
        }
        return Result.ok(shop);
    }


//    private Shop queryWithLogicalExpire(Long id){
//        String shop = stringRedisTemplate.opsForValue().get(CACHE_SHOP_KEY + id);
//        if (StrUtil.isBlank(shop)){
//            return null;
//        }
//
//        //命中，需要把json反序列化为对象
//        RedisData bean = JSONUtil.toBean(shop, RedisData.class);
//        JSONObject shop1 = (JSONObject) bean.getData();
//        Shop shop2 = JSONUtil.toBean(shop1, Shop.class);
//        LocalDateTime expireTime = bean.getExpireTime();
//        //反序列化结束判断是否过期
//        if (expireTime.isAfter(LocalDateTime.now())){
//            //未过期，直接返回
//            return shop2;
//        }
//        //已过期，需要缓存重建
//        //缓存重建
//        //获取互斥锁
//        String key = RedisConstants.LOCK_SHOP_KEY+id;
//        boolean isLock = tryLock(key);
//        //判断是否获取锁成功
//        if (isLock) {
//            //成功，开启独立线程，实现缓存重建
//            CACHE_REBUILD_EXECUTOR.submit(()->{
//                try {
//                    this.saveShop2Redis(id,30L);
//
//                } catch (Exception e) {
//                    throw new RuntimeException(e);
//                } finally {
//                    unLock(key);
//                }
//            });
//
//        }
//        //失败，返回店铺信息
//            return shop2;
//        //
//
//
//    }
//    private static final ExecutorService CACHE_REBUILD_EXECUTOR = Executors.newFixedThreadPool(10);

//    private Shop queryWithMutex(Long id) {
//        String shop = stringRedisTemplate.opsForValue().get(CACHE_SHOP_KEY + id);
//        if (StrUtil.isNotBlank(shop)){
//            return JSONUtil.toBean(shop, Shop.class);
//        }
//        //判断是否为空值
//        if(shop != null){
//            //返回错误信息
//            return null;
//        }
//
//        //开始实现缓存重建
//        //1.获取互斥锁
//        String lockKey = "lock:shop:"+id;
//        Shop shop1 = null;
//        try {
//            boolean isLock = tryLock(lockKey);
//            //2.、判断是否获取成功
//            if (isLock == false){
//                //3.失败休眠
//                Thread.sleep(50);
//                return queryWithMutex(id);
//            }
//
//
//            //4.成功操作数据库
//            shop1 = getById(id);
//            Thread.sleep(200);
//            if (shop1==null) {
//                stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,"",2L,TimeUnit.MINUTES);
//                return null;
//            }
//            stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(shop1),30L, TimeUnit.MINUTES);
//            //7.释放互斥锁
//        } catch (InterruptedException e) {
//            throw new RuntimeException(e);
//        } finally {
//            unLock(lockKey);
//        }


//        return shop1;
//    }

    @Override
    @Transactional
    public Result update(Shop shop) {
        Long id = shop.getId();
        if (id==null) {
            return Result.fail("店铺id不能为空");
        }
        //更新数据库
        updateById(shop);
        //删除缓存
        stringRedisTemplate.delete(CACHE_SHOP_KEY + id);
        return Result.ok();
    }

//    @Override
//    public void saveShop2Redis(Long id, Long expireSeconds) throws InterruptedException {
//
//    }

//    public Shop queryWithPassThrough(Long id){
//        String shop = stringRedisTemplate.opsForValue().get(CACHE_SHOP_KEY + id);
//        if (StrUtil.isNotBlank(shop)){
//            return JSONUtil.toBean(shop, Shop.class);
//        }
//        //判断是否为空值
//        if(shop != null){
//            //返回错误信息
//            return null;
//        }
//        Shop shop1 = getById(id);
//        if (shop1==null) {
//            stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,"",2L,TimeUnit.MINUTES);
//            return null;
//        }
//        stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(shop1),30L, TimeUnit.MINUTES);
//        return shop1;
//    }


//    private boolean tryLock(String key){
//        Boolean b = stringRedisTemplate.opsForValue().setIfAbsent(key, "1", 10, TimeUnit.SECONDS);
//        return BooleanUtil.isTrue(b);
//    }
//
//    private void unLock(String key){
//        stringRedisTemplate.delete(key);
//    }

    public void saveShop2Redis(Long id,Long expireSeconds) throws InterruptedException {
        //1.查询店铺数据
        Shop shop = getById(id);
        Thread.sleep(200);
        //2.封装逻辑过期时间
        RedisData redisData = new RedisData();
        redisData.setData(shop);
        redisData.setExpireTime(LocalDateTime.now().plusSeconds(expireSeconds));
        //3.写入redis
        stringRedisTemplate.opsForValue().set(CACHE_SHOP_KEY+id,JSONUtil.toJsonStr(redisData));
    }

    @Override
    public Result queryShopByType(Integer typeId, Integer current, Double x, Double y) {
        //1.是否需要按坐标查询
        if(x==null || y==null){
            //不需要坐标查询，按数据库查

            Page<Shop> page = query()
                    .eq("type_id", typeId)
                    .page(new Page<>(current, SystemConstants.DEFAULT_PAGE_SIZE));
            // 返回数据
            return Result.ok(page.getRecords());
        }
        //2、设计分页参数
        int from = (current-1)* SystemConstants.DEFAULT_PAGE_SIZE;
        int end = current * SystemConstants.DEFAULT_PAGE_SIZE;
        //3.查询redis、按照距离排序，分页
        String key = SHOP_GEO_KEY+typeId;
        GeoResults<RedisGeoCommands.GeoLocation<String>> results = stringRedisTemplate.opsForGeo().search(key, GeoReference.fromCoordinate(x, y),
                new Distance(5000),
                RedisGeoCommands.GeoSearchCommandArgs.newGeoSearchArgs().includeDistance().limit(end)
        );
        //4.解析出id
        if (results == null){
            return Result.ok();
        }
        List<GeoResult<RedisGeoCommands.GeoLocation<String>>> content = results.getContent();
        if (content.size()<=from){
            //没有下一页了，结束
            return Result.ok(Collections.emptyList());
        }
        //4.1截取from - end
        List<Long> ids = new ArrayList<>(content.size());
        Map<String,Distance> distanceMap = new HashMap<>(content.size());
        content.stream().skip(from).forEach(result -> {
            String shopIdStr = result.getContent().getName();
            ids.add(Long.valueOf(shopIdStr));
            //4.3获取距离
            Distance distance = result.getDistance();
            distanceMap.put(shopIdStr,distance);
        });

        //5.根据id查询shop
        String idStr = StrUtil.join(",", ids);
        List<Shop> shops = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + " )").list();
        for (Shop shop : shops){
            shop.setDistance(distanceMap.get(shop.getId().toString()).getValue());
        }
        //6.返回
        return Result.ok(shops);
    }
}
